Rotary switch with floating contact arm



Jan. 16, 1951 v R. D. TAYLOR 2 ,538,174

ROTARY swxwcn WITH momma CONTACT ARM Filed Aug. 26, 1949 2 Sheets-Sheet1 u hi I 40 Inventor Roderic 0. Taylor 9 By @nmM W a Attorneys Jan. 16,1951 R. D. TAYLOR ROTARY SWITCH WITH FLOATING CONTACT ARM Filed Aug. 26,1949 I n uentor Roderic 0. Taylor Patented Jan. 16, 1951 UNITED STATESPATENT OFFICE ROTARY SWITCH WITH FLOATING CON'IIACT ARM Roderic D.Taylor, Pacific Palisades, Calif.

Application August26, 1949, Serial N0.,112,.47.7

Claims.

This invention relates to rotary switches and more particularly toswitches associated with rotating members, one of which is connected,with a contact arm while the other is provided. with a number ofcontacts and it has. for its primary object to provide av rotary switchof the above named type which. makes or breaks con.- nection after apredetermined relative an ular movement of the said, members and which;is operative without any appreciable reaction of one rotatable member onthe other.

It is, a further principal object of the invention to provide a rotaryswitch of. the above named type in which one of the two rotary membersis, held in its position merely by a magnet. which is under theinfluence of an external magnetic field, said switch bein operative as.soon as. the. second rotary member has. performed a relative rotationwith respect to the member held. by the. magnet without producing adisplacement. of. the.

same.

It is a further objectv of the, invention. to pro.- vide meanspermitting an operation of. a retary switch of the type above mentionedupon a. predetermined angular movement. without appreciable reaction ordisplacement of, the members held in relatively fixed positions, said.means. consisting of an annular mercury container. andv a floatsupporting the rotatable contact arm connected with the member held in arelatively fixed position in space.

It is a further object of the invention to provide means for holding oneof the members. by means of the magnetic force of the earth said meansconsisting of a series of magnet needles which are mounted on a shaftand which are separated by insulating mica disks covered with enamelpaint.

It is a further object of the invention to. pro vide means forsupporting the contact arm of the switch which consists of a toroidal orannular mercury container, disposed around and; coaxially with the axisaround which rotation of the two members takes place, said containerwhen filled with mercury carrying an annular float member fixedlyconnectedwith the contact arm of the switch, cooperatin with contactswhich are fixedly connected with the second r0. tary member.

It is a further object of the invention to provide a switch which isoperative upon a predetermined angular displacement of two coaxial.rotating members, one of which includes rotatable magnets held by anexternal magnetic.

field while, the other member, which is subjected to rotation around theaxis of rotation of the first named member, carries contacts and an annuliar mercury container disposed around the axis of' rotation of themembers, said container being filled with mercury supporting a floatmember adapted to move around the common axis of" the rotating membersand connected with the contact arm. of the, switch which cooperates withcontacts on the second member.

Further objects of" the invention will be apparent from the followingdetailed. specificatlon.

The invention is described? with reference to the accompanying drawin showing one embodiment thereof by way oi example. It is however to. beunderstood that the example shown has been selected in order to explainthe principle of the invention and the best mode of applying saidprinciple. The example shown in the drawing does. not illustrate furthermodes of ppli a on ot he principle. of the invention some of which areobvious. to. those skilled in the art, but it will be clear thatmodifications of the examp e shown will not necessarily involve adeparture from the principle of the invention.

.In the. accompanying drawin Figure 1 is. a sectional elevational, View,the section being taken along the plane of symmetry passin through linel--l. of Fi ure 4;

Figure 2 is a sectional elevational view of the pper partof the rotaryswitch, the section being taken alon line 22 ofFigure 4;

Figure 3 is a plan view of the rotary switch;

Figure 4 is a, sectional plan view, the section. being, taken along line4.-4. of Figure 2;

Figure 5 is another sectional, plan view, the section being taken. alongline. 5-5 of Figure 1;

Figure 6. is, another sectional plan view of the rotary switch, thesection being taken along line 6-6. of Figure 2;.

Figure. 7 is. a. sectional plan view through the rotary switch, thesection being taken along line 11 of Figure 1;

Figure 8. is an elevational view of a door panel, carrying the switch;

Figure 9 lsan end view of the can as seen from a. plane. indicated. atQTB. in Figure 2.

The switching device according to the invention comprises, acylindrical, tubular container ID of non-magnetic material which may bedouble walled, the two walls being formed by two concentric cylindrical,tubes ll, l2 spaced by suitable spacing sleeves [3 which are held bybolts 23. The tubular container may be closed at its. lower end by meansof threaded pl s 35 or closure disk. The container is subdivided alongits longitudinal axis into several compartments separated by insulatingdisks forming partition walls 14, I8. The first compartment may beformed by partition wall 2| in the lowermost part of the container andthis compartment may contain a stop watch mechanism l5 mounted on theclosure disk or plug 35 and a further mechanism which is operated by theswitch, such as a counter mechanism l6, for example, the mechanism beingshown as operated by a solenoid or electromagnet IT. A further disk orpartition wall in the compartment contained between the two partitionwalls 2| and I4 may carry a jeweled thrust bearing [9 for a Verticalshaft 26] carrying magnetic needles 22 or other magnets which areinfluenced by an external magnetic field such as the magnetic field ofthe earth or any other artificially produced magnetic field.

, According to the invention a number of mag-. netic needles 22 may bemounted on the shaft and between them a number of insulating disks 24preferably made of mica and covered with an enamel paint are arranged,which disks may be carried by a sleeve 25 encircling shaft 2t. Theenameled mica disks increase the magnetic reluctance for the unwantedmagnetic field pro duced between the magnetic needles.

The shaft 20 may be pointed at the end supported on the jeweled bearingis and the partition walls l4, l8 through which the shaft passes may beprovided with sleeve bearings 28a holding the rotatable shaft 20.

The upper end of the shaft 20 supports and carries a cup-shaped member26 which is pro vided with internal teeth and thus forms an internalgear wheel meshing with a planetary gear wheel 28 which engages acentral gear wheel 29 mounted on a shaft 30. The gear wheel 29 mayeither be of a sufiicient width to be kept in engagement with wheel 28even upon a limited axial displacement or the said gear wheel may becoupled with the shaft 30 merely for rotation but may be mounted in sucha way that the shaft 30 while preserving the rotational engagement withthe gear wheel may slide in axial direction in a limited way.

The shaft 30 is supported by a transverse contact arm 32 which isprovided with contact rollers 33 at its ends which are preferablyforked. These contact rollers may contact with fixed contacts which aredescribed below. The contact arm 32 is held by means of suitable angularsupporting brackets 38 on the upper part or cover of a mercury float 34which consists of a number of ball-shaped floats or buoyancy members 35which have been joined by means of an annular piece 35 of arcuate crosssection (Figure 5) preferably made of a translucent plastic. The axis ofsaid annular member 35 is coincident with the axis of the shaft and. ofthe tubular container. V

The float or buoyancy bodies 35 are fixed to the annular member 36 bymeans of rivets or pins so thatthe balls and the annular member form asingle float member 34 supporting the contact arm by means of thebrackets 38. This float member may rotate with the shaft 39 and aroundthe axis of the shaft.

The float member 34 is held within a toroidal container 40 of a crosssection which is b,owl shaped or ovoidal with a flat bottom and an opentop. It will be understood that on account of the toroidal shape of thecontainer 40 the opening at the top is annular. The axis of the toroidalcontainer 44 is coincident with the axis of the shaft 30 and of thetubular container [6, so that any movement of the float 34 will onlyresult in a relative rotational movement of the float within thecontainer but will not change the distances or relative positions in atrans verse plane passing through the axis of the shaft 30. Thecontainer is preferably made of a translucent plastic.

It will thus be clear that the float member 34 may move within the bowlshaped toroidal member' 40 while rotating around the axis of thecontainer [0 and of the shaft 30.

The toroidal container of bowl shaped cross section is filled withmercur as indicated at 4| and the float member 34 floats on and ispartly submerged in the mercury held within the said container 49.

The toroidal container 46 rests on a further disk member 42 which isprovided with a central sleeve-like projection 43 through which theshaft 30 may pass. The sleeve is held by means of long screw bolts 44,45 (Figure 1) passing through sleeves 46 to the outside of thecontainer. The screw bolts may be provided with knurled heads. Thesleeves are threaded and the screw bolts may be applied against flatouter surfaces of the sleeve-like projection 43 so as to hold the latterfirmly between them.

The sleeves 46 pass through slots 53 of the inner tubular container [2;the latter is held at this end by means of spring pressed spacing screws54.

The upper end of the tubular container [0 is closed by means of a cap 48engaging one of the tubular members II and seated preferably on aninsulating ring 45 joining the two tubular members H and I2. This cap 48is provided with a central opening at its top which is covered by atransparent disk or plate 5!] preferably made of a transparent plasticwhich may be provided with a graduation along the periphery of a circlethe center of which is located in the axis of the shaft 30 which is alsocoincident with the axis of the body ID. As will be seen in Figures 1and 3 the contact arm 32 moves immediately below the said opening and itis therefore possible to observe the movement of the shaft 30 and tonote if necessary the angular displacement of the contact arm 32.

The transparent disk 50 is held in place by a closure cap 5| pressedupon the cap 48.

The cap may be held in its position frictionally by means of a flatspring 61 applied against the tube II.

On the inside of the cap 48 insulated blocks or strips are mounted whichcarry contact springs 56 adapted to cooperate with the contact rollers33 of the contact arm 32. These contact springs may be connected withcopper inserts 58 sliding on a copper ring 59 which is held by theinsulating ring 49. The copper inserts 58 are connected with the contactsprings 53 by means of bolts or by wires which are passing through thecap and which are insulated therefrom.

Obviously the number of contact springs and their shape is dependent onthe specific application of the floating switch. In the example shownleaf springs have been illustrated which are somewhat projecting intothe interior of the cap and are pressed back by the contact rollers 33when the contact arm 32 moves over them so as to pro-- duce goodcontact. The position of the spring relatively to the rollers may beadjusted by adjusting screws 68 which are provided in the cap and whichmay be "adjusted in order to adjust the contact between the leaf:springs' :and the rollers. The example shown in the drawing illustratesa construction in which :contact is only established once whena certainangular .deviation of the two movable members has been reached.Obviously, however, the insulated ring may be provided with a largernumber of inlaid surface contacts in the manner of a commutator,

over which the contact rollers 33 of the contact arm 32 may move. Eachcontact in this case is led to a separate terminal. I

In the example shown the contact spring 56 on one side is joined to thecopper insert 58 which in its turn is connected with the mercurycontainer 40 by means of wire 62 leading to a further terminal post 69passing through the bottom portion of said toroidal container 40 oftranslucent pl'astic. At a second terminal post 6| passing through thebottom of said container 40 a, connection may be made with the source ofcurrent by means of a wire 63. At the second copper insert 58 on theright side of Figure 2, a further connection is indicated in the form ofa wire 64.

Wire 64 as shown in Figure 1 may lead to the solenoid ll of the countermechanism IS, the other terminal of which may be connected with thesource of current by means of wire 65. Both wires may run through thehollow space between the two tubes ll, !2 and are led to the outsidethrough an insulating sleeve 66 in the outer tube H which is located atan appropriate place.

If the magnetic needles are held in a certain position in space by themagnetic field of the earth and if the container I6 is secured to arotating object which rotates around the axis of the shafts 26 and 36which is coincident with the axis of the container l0, then it will beclear that the counter I6 and the stop watch mechanism l5 are operatedas soon as the tubular container [0 has been rotated through a certainangle. Attention is called to the fact that such an angular movement hasbeen translated by means of the gear wheels 21, 2B, 29, so that theaxial angular movement of the container l0 relatively to the fixedposition of the needles may be either larger or smaller than themovement performed by the contact arm 32. As an example the switch maycontrol or register the opening of a door. The container ID in this caseis mounted vertically within a, hole 69 in the door panel 16. A movementof the door to a certain extent for instance to the extent necessary forthe passage of a person will then be registered by means of the counter.

It will be clear that a change of an unessential nature will not involvea departure from the invention as claimed in the annexed claims.

Having described the invention, what is claimed as new is:

1. A rotary switch comprising a tubular container, a contact arm with aslide contact moving along the inner surface of said container,peripheral contacts substantially arranged in and along the innercontainer surface, swept by the slide contact, a shaft connected withsaid contact arm, a toroidal container of bowl shaped cross sectionfilled with a conducting liquid, fixed within said container, an annularconducting float member, floating in the liquid filled toroidalcontainer, supporting said contact arm and in conducting connection withthe same, contacts in the toroidal container provided with connectingmeans for producing a connection with said float carried contact armincluding the conducting liquid and float member, means for producing arelative angular movementof the tubular container relatively to theshaft and contact .arm, and means for holding one of said members in afixed position in space.

2. A rotary switch comprising a tubular container, a radial contact armwith a slide contact moving along the inner surface of said container,peripheralcontacts substantially arranged in and along said innercontainer surface, swept by the slide contact, shaft coaxial with thecontainer axis, connected with saidcontact arm, a toroidal container ofbowl shaped crossed section, filled with a conducting liquid,fixedly-held within said container and coaxial with the said shaft, anannular conducting float member including buoyancy members floatingwithin the liquid in the toroidal container and supporting the saidcontact arm and shaft, further contacts in the toroidal containerprovided with connecting means for producing a connection with thecontact arm including the conducting liquid and float member, a furtherindependently supported and separately rotatable shaft coupled with thefirst named shaft within said tubular container and magnetized memberscarried by said further shaft subjected to the influence of an externalmagnetic field.

3. A rotary switch comprising a cylindrical tubular container. a radialcontact arm within said container, an open toroidal container of bowlshaped cross section, coaxial with the cylindrical container carried bythe tubular container, said toroidal container being filled with aliquid, a float consisting of buoyancy members floating in the liquidheld in the toroidal container and of an annular member joining saidbuoyancy members, said float being coaxial with and held within thetoroidal container, brackets projecting outwardly through the openportion of the toroidal container and supporting said contact arm,contacts in the interior of the tubular container cooperating with thecontact arm, magnetic means for holdin said contact arm under theinfluence of an external magnetic field, and means for producing arelative rotation between said contact arm and said tubular container.

4. A rotary switch as claimed in claim 3, wherein the contact arm islocated at one end of the tubular container, a cap with a transparentplate provided with a graduation on said end of the tubular container,the graduation indicating the relative angular displacement of thecontact arm and the tubular container.

5. A rotary switch comprising a double walled tubular cylindricalcontainer, consisting of two spaced concentrically arranged tubes, acylindrical cap at one end of the tubes carrying fixed contacts arrangedalong its inner cylindrical surface, a contact arm rotatablearound theaxis of the cylindrical tubes, sweeping over and cooperating with saidfixed contacts, a toroidal container of bowl shaped cross section openat the top, held within and arranged coaxially with said tubularcontainer, said toroidal container being filled with mercury, an annularfloat within said toroidal container coaxial with the-same including anannular member, with a number of buoyancy bodies attached to it floatingon the mercury, said contact arm being supported on said annular floatby brackets passing through the open top portion of the toroidalcontainer, a

shaft in the axis of the tubular container, pro- 7 vided withlongitudinally spaced magnetic members, and means for coupling saidshaft with said contact arm.

6. A rotary switch as claimed in claim 5, Wherein the shaft carrying themagnetic members is coupled with an internal gear wheel, further gearwheels meshing with said internal gear wheel, a further shaft rotativelycoupled with one of the last named gear wheels, said further shaft beingconnected with the contact arm.

7. A rotary switch as claimed in claim 5, wherein fixed contacts arearranged at diametrically opposite portions of the cap and wherein thecontact arm is disposed along a diameter of the tubular container and isbridging and connecting contacts arranged at diametrically oppositeportions of the cap.

8. A rotary switch as claimed in claim 5 wherein the fixed contacts inthe cap consist of leaf springs.

RODERIC D. TAYLOR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 980,155 Hertzberg Dec. 27, 1910

